CLI-3560: invalid memory address or nil pointer dereference when consuming a topic using a context

There is an error when using contexts when consuming from a topic
```
confluent kafka topic --context dev
Error: runtime error: invalid memory address or nil pointer dereference
```

CLI details:
```
confluent - Confluent CLI

Version: v3.40.0
Git Ref: 299e722ef
Build Date: 2023-11-02T23:32:56Z
Go Version: go1.21.0 X:boringcrypto (windows/amd64)
Development: false
```